By far Pyongyang's most important trade partner China accounted for $5.6 billion of the total.

Analysts told Yonhap News that North Korea earned the bulk of its foreign revenues from selling raw materials to China, including coal.

Deposits in many existing coal mines are reportedly close to exhaustion and prices within North Korea have risen dramatically, but the government is still exporting much of its total production in order to earn the currency that it requires to pursue its nuclear weapons and missile programmes.

Major imports from China included 3.8 million barrels of crude oil, naphtha products, cargo vehicles with a total value of $92.2 million and more than $58 million worth of flour.

There was also positive news in North Korea's food production, with the World Food Programme and the UN Food and Agriculture Organisation suggesting that rice production increased 11 per cent on the previous year while the corn crop was up by 10 per cent.